The invention relates to improvements in winder drums supportingly driving a roll, such as paper being wound from a continuous traveling web. More specifically, the invention relates to winder drums having a compliant covering which has a discontinuous, circumferentially interrupted pattern in its surface.
In high speed winding wherein a roll is wound from a web of paper onto a core, the web travels at speeds in excess of 4,000 feet per minute, and it is imperative that the winding progress uniformly so as to maintain a desired tension of the web on the roll and insure that the wound roll is as free as possible from defects. In this type of winder, one or two winding drums drive the wound roll, and at the high winding speeds, an undesirable noise is generated, requiring paper mill personnel to wear noise-reducing ear plugs. This noise adds to the general overall noise of other equipment and is undesirable. Where a uniform groove pattern is utilized on the drum, a tonal, or frequency specific noise, is generated by the repetitive rotation of the uniform groove. Another disadvantage of existing drums is that a drum, whether having a hard outer surface or a compliant covering, affects the web and roll differently as the roll builds up in weight. Further, undesirable induced tension in the web can result in a defective roll with crushing, tears, and wrinkles or ridges in the paper web. A standard groove or void pattern for both non-compliant and compliant covered drums utilizing the winding process is repetitive and uniform in both the machine and cross-machine directions. During the winding process, a tonal noise is produced by the repetitive sequence of a continuous, circumferentially extending void or groove area followed by a high, or protruding, or ridge area of the drum, which alternate in the longitudinal, or axial, direction with the ridge areas supporting the winding roll of web material. This continuous and tonal noise frequency or pitch is a function of a grooved drum, drum diameter, and linear, or web, speed of the machine. The foregoing problems are true whether a single drum winder is used or a twin drum winder wherein the winding roll is carried in the nest between two parallel drums.
An object of the invention is to provide an improved winding drum for use in high speed winders which substantially reduces or eliminates the noise generated between the winding drum and the roll.
A further object of the invention is to provide an improved winding drum having a compliant covering with recesses in the surface which reduce winding nip-induced tension in the wound roll of material.
A still further object of the invention is to provide an improved winding drum which avoids disadvantages of structures heretofore available and provides a surface of compliant material with recesses wherein the recesses are unique in shape, spacing and size, area and application of the area contacting the wound roll, thereby alleviating problems of induced tension and generated noise.